Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

Porsche 924 Racecar Build Thread (AAN Conversion)
Goto page Previous  1, 2, 3, 4, 5
 
Post new topic   Reply to topic    924Board.org Forum Index -> Performance Upgrades
View previous topic :: View next topic  
Author Message
924RACR  



Joined: 29 Jul 2001
Posts: 8374
Location: Royal Oak, MI, USA

PostPosted: Fri Sep 04, 2020 10:10 pm    Post subject: Reply with quote

Very impressive work!

Really like the diffuser... will be even sexier in carbon..
_________________
Vaughan Scott
Webmeister
'79 924 #77 ITB racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
Back to top
View user's profile Send private message Send e-mail Visit poster's website
kondzi  



Joined: 02 Jul 2018
Posts: 143
Location: MZ/Poland/EU

PostPosted: Sat Sep 05, 2020 7:37 am    Post subject: Reply with quote

Really enjoying that metal work (alloy work). Good stuff!
_________________
---
Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)
Back to top
View user's profile Send private message
Britain  



Joined: 26 Nov 2013
Posts: 191
Location: Hillsboro, OR

PostPosted: Tue Sep 08, 2020 4:36 am    Post subject: Reply with quote

Few more technical updates for this thread.

We kept having issues with the T3 flange bolts on the cast manifold coming loose and wanted to go with an slightly bigger turbo so I went about building a stainless manifold.

Started off cutting an exhaust flange on the waterjet and then had recessed cut into it on a friends CNC.


Then the cast stainless bends register right into these recesses.


Here is the log part of the manifold completed.


Then the up-pipe to the turbo was fabricated with the WG port.


Here is the manifold with the Garrett turbo hanging off it.


And the new v-band downpipe to go with it.
Back to top
View user's profile Send private message
Britain  



Joined: 26 Nov 2013
Posts: 191
Location: Hillsboro, OR

PostPosted: Tue Sep 08, 2020 4:36 am    Post subject: Reply with quote

The next things to address is more heat management.

First up with another oil cooler to add to the system. Now the oil comes from the engine thru this cooler first and then thru the oil-water heat exchanger. This reduced both the oil temps and the water temps which was the intended result.

Here is the oil cooler mounted off the front sub-frame:


And a scoop that fits flush to the front valance:


Next up was to reduce in intake air temps a bit. This turbo has a wider powerband so we are seeing boost long and therefore increased IAT's.

To start, I purchased a huge Garret intercooler core. This one is rated for 1200hp. The primary purpose for this size core was to get the depth that closely matched the stock unit.



I then proceeded to cut it in half which gave me a core that was 4.5" deep, 7" tall, and 22" wide (the stock 944 turbo core is 5" deep, 5.5" tall, and 18" wide)


Here is the comparison with the end-tanks welded on:




And mounted in the car with the fencing adjusted to match the increased width.
Back to top
View user's profile Send private message
CÚdric  



Joined: 27 Aug 2004
Posts: 2079
Location: Sweden

PostPosted: Tue Sep 08, 2020 6:01 am    Post subject: Reply with quote

Nice that you keep updating the thread. Have you though about doing a more ambitious extractor scoop on the bonnet. If you want to improve the efficiency of the radiators?
_________________
1980 924 Turbo
Back to top
View user's profile Send private message MSN Messenger
Britain  



Joined: 26 Nov 2013
Posts: 191
Location: Hillsboro, OR

PostPosted: Tue Sep 08, 2020 8:07 am    Post subject: Reply with quote

CÚdric wrote:
Nice that you keep updating the thread. Have you though about doing a more ambitious extractor scoop on the bonnet. If you want to improve the efficiency of the radiators?


Yeah....space is a bit tight, but I am going to make something. There is a balance to ensuring we have ability to address things quickly during the race.

-Britain
Back to top
View user's profile Send private message
kondzi  



Joined: 02 Jul 2018
Posts: 143
Location: MZ/Poland/EU

PostPosted: Tue Sep 08, 2020 8:14 am    Post subject: Reply with quote

I need to master Aluminium TIG welding, that's a must
Tried a bit, but it's quite difficult, or it's just beginners issues.
Good to have friends with CNC capable to shape stainless, anyone with CNC shop wants to be my friend?
_________________
---
Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)
Back to top
View user's profile Send private message
Britain  



Joined: 26 Nov 2013
Posts: 191
Location: Hillsboro, OR

PostPosted: Thu Dec 31, 2020 7:09 am    Post subject: Reply with quote

Well...2020 may of been a **** year...but the Porsche 924 has taken the overall win and Lucky Dog Racing championship for a 2nd year in a row. This year was a dogfight with so many very fast cars backed by some large shops and fast drivers. Over 120 cars started the 14hr race and the margin of victory at the end was less than half a lap. We were able to complete the race with zero mechanicals or black flags.

Check out the field at the start of the race:


Checkered Flag:


Podium Shot:


It wasn't all fun and games...during the practice day on the Friday we blew 105db and were forced to hack up the stainless exhaust system and graft in a muffler from the local autoparts store.



Then we had a throwout bearing issue and for those who have changed a clutch on these cars knows that it is quite an job to tackle as just about everything underneath has to be pulled out of the way.



At the of the race we completed just under 1000miles around the 5mile course.
Back to top
View user's profile Send private message
Britain  



Joined: 26 Nov 2013
Posts: 191
Location: Hillsboro, OR

PostPosted: Thu Dec 31, 2020 7:10 am    Post subject: Reply with quote

Now back to the technical stuff.

In the 6 or so years of running this car we have managed to bugger up 3 steering racks. The ability to find used racks for these cars is getting increasing difficult so it is time to find a better solution. The solution path I wanted to take was use the internals of the right-hand VW rack and the stock 924 housing. The ratio is a bit quicker, however the bearing for the pinion shaft was a bit larger diameter and wouldn't fit. We bored the hole a little larger to fit the bear and voila we have a fresh steering rack. The shaft is about 0.5" longer so I also had to modify the intermediate shaft in the steering column to account for the difference.

Stock Rack on Top, VW Rack in middle, and gutted 924 Rack on Bottom:


Bearing Carrier hole bored a bit larger:


Differences in the shafts:


924 rack rebuilt with VW Internals:
Back to top
View user's profile Send private message
morghen  



Joined: 21 Jan 2005
Posts: 8277
Location: Romania

PostPosted: Thu Dec 31, 2020 6:41 pm    Post subject: Reply with quote

Nice to finally see the rhd vw rack fix in pictures.
How many turns from end to end with the vw internals?
_________________
SUPERCHARGED Ruby-sh 924
Back to top
View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
peterld  



Joined: 10 Dec 2006
Posts: 811
Location: Noosa Heads QLD Australia

PostPosted: Fri Jan 01, 2021 12:18 am    Post subject: Reply with quote

Well done on a most successful year. Well deserved after so many trials and tribulations with the Toofah!

And keep those updates coming.....such interesting stuff.
_________________
80/81 932/8 ROW
Back to top
View user's profile Send private message Send e-mail
Britain  



Joined: 26 Nov 2013
Posts: 191
Location: Hillsboro, OR

PostPosted: Tue Jan 12, 2021 4:40 pm    Post subject: Reply with quote

Not much of a break this year as our first race of the season is Laguna Seca next weekend. First up is to address the exhaust manifold and find a better, more reliable solution to the log manifold set-up. The main reason I had held off in building a tubular manifold was because I couldn't find a good source for a cast or billet stainless collector for a 5-cylinder engine. With the increase in people tuning V-10 cars and the newer 07K Audi 5-cylinder, these are finally available.

So, I spent the last week constructing a new manifold centered around a billet 5-cylinder collector I got from Jaaatt Engineering. The primary runners are 1.25" and then I run an 2" up-pipe to the GT2860RS turbo mounted down below a bit. The space is tight in here and I had to make sure we could install/remove the manifold without having to pull the engine.

To aid in the effort, I used the CAD files for the cast stainless elbows from McMaster and added cut lines every 15degs for reference. I got the reference location for the collector to the first cylinder and laid out the rest on the welding table as I went along. It was challenging to route and weld, but it turned out great and ran great on the dyno.











Back to top
View user's profile Send private message
Britain  



Joined: 26 Nov 2013
Posts: 191
Location: Hillsboro, OR

PostPosted: Tue Jan 12, 2021 4:40 pm    Post subject: Reply with quote

As you can see, the space in the chassis is tight. I even had to clearance a bit off the shock tower to gain another ~1" of clearance.









Back to top
View user's profile Send private message
Britain  



Joined: 26 Nov 2013
Posts: 191
Location: Hillsboro, OR

PostPosted: Tue Jan 12, 2021 4:40 pm    Post subject: Reply with quote

Before you ask for HP numbers, we also had to add about 10ft of exhaust routing and a very large muffler to meet sound restrictions at the upcoming race at Laguna Seca next weekend. We will get true numbers after this race with the previous exhaust set-up installed.

Here is a look at the crazy routing for the exhaust...not shown here in the diffuser which is why the exhaust has this crazy routing.










For extra insurance, I have another exhaust extension that can be bolted to the outside of the car...bit hillbilly style.
Back to top
View user's profile Send private message
Britain  



Joined: 26 Nov 2013
Posts: 191
Location: Hillsboro, OR

PostPosted: Tue Jan 12, 2021 4:41 pm    Post subject: Reply with quote

Another edition of..."***** that could of ended our race". Here is 4th gear. The was the whine noise we were hearing at Thunderhill. We spend probably 80% of all our track time in this gear and have this set-up together for over 2years so I am not surprised. Found a nice replacement here on Pelican and got it rebuilt and back in the car.





Didn't mention it earlier but I also built a new strut brace using a set up tube connectors. This should help with any chassis flex we are getting in the front suspension.



Also had to do some repair to the front splitter after a season of abuse. I will be constructing version 2.0 soon, but for now I needed to get the current set-up back together. It was pretty beat up and required a little bit of bondo to fill the voids...much better now.





Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> Performance Upgrades All times are GMT + 11 Hours
Goto page Previous  1, 2, 3, 4, 5
Page 5 of 5

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group